Liquid crystal display panel

ABSTRACT

A liquid crystal display panel divided into a first and a second regions respectively having a plurality of sub-pixels arranged in array is provided. Each sub-pixel has a first display area providing a first main alignment vector, a second display area providing a second main alignment vector, and a compensation display area. A direction of the first main alignment vector is opposite to that of the second main alignment vector. When the liquid crystal display panel states in the narrow viewing angle display mode, driving voltages of the first display areas in the first region are substantially greater than driving voltages of the second display areas in the first region, driving voltages of the first display areas in the second region are smaller than driving voltages of the second display areas in the second region, and all the compensation display areas in the first and the second regions are enabled.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. application Ser.No. 13/207,416, filed on Aug. 11, 2011, now allowed. The prior U.S.application Ser. No. 13/207,416 claims the priority benefit of Taiwanapplication serial no. 100115775, filed on May 5, 2011. The entirety ofeach of the above-mentioned patent applications is hereby incorporatedby reference herein and made a part of this specification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention generally relates to a liquid crystal display (LCD) panel,and more particularly, to an LCD panel having the privacy protectingfunction.

2. Description of Related Art

Recently, the display device is required to have the wide-viewingcharacteristic when displaying images so as to satisfy the demand that aplurality of users simultaneously watches the displayed images of thesame display device. Nevertheless, under certain conditions, such aswriting business information or inputting personal account number andpassword into the ATM machine, the wide viewing characteristic of thedisplay device may cause the reveal of user's personal information.Accordingly, the display device needs the privacy protecting designs forpreventing the highly confidential data from being seen.

At present, a privacy protecting design is provided and achieved byusing the alignment design of the LCD panel. In such privacy protectingtechnology, the LCD panel is used for providing the displaying functionin the display device. Generally, the LCD panel is disposed between twopolarizers, while the directions of the light transmission axis of thetwo polarizers respectively are configured parallel to the linedirection and the row direction in the pixel array of the LCD panel.Namely, the light transmission axes of the two polarizers arerestrictedly located in 0 degree azimuth angle and 90 degree azimuthangle and the light transmission axes of the two polarizers are includedwith each other by 90 degrees. Meanwhile, the LCD panel is divided intotwo regions such as the first region and the second region.

The changes of brightness with variant polar viewing angles and variantazimuth viewing angles have different tendencies in the first region andthe second region of the LCD panel. Herein, the polar viewing anglemeans the included angle between the watching direction of the user andthe baseline when the normal viewing angle direction (defining 0 degreepolar viewing angle) is served as the baseline (i.e. the normal line ofthe LCD panel) and the azimuth viewing angle means the included angle inthe horizontal surface between the watching direction of the user and ahorizontal axis direction. By using such design, the LCD panel can havethe privacy protecting function. The brightness distribution of theknown LCD panel under different polar viewing angles is described in thefollowing.

FIG. 1 shows the relationship between the displayed brightness presentedby a conventional LCD panel under the privacy protecting mode and thecorresponding polar viewing angles when the LCD panel is watched atvariant polar viewing angles along the horizontal axis direction (thatis, the direction parallel to the 0 degree azimuth viewing angle or the180 degree azimuth viewing angle). Referring to FIG. 1, the curve 110shows the relationship between the displayed brightness presented by thefirst region of the LCD panel and the polar viewing angles when the LCDpanel under the privacy protecting mode is watched at variant polarviewing angles along the horizontal axis direction and the curve 120shows the relationship between the displayed brightness presented by thesecond region of the LCD panel and the polar viewing angles when the LCDpanel under the privacy protecting mode is watched at variant polarviewing angles along the horizontal axis direction, wherein the polarviewing angle at the normal viewing angle direction is, for instance,defined as 0 degree and the normal viewing angle direction means thatthe watching direction of the user is perpendicular to the outer surfaceof the substrate of the LCD panel. Herein, the normal viewing angledirection is defined as the position of the 0 degree polar viewing angleand the outer surface of the substrate of the LCD panel is defined asthe position of the 90 degree polar viewing angle.

As shown in the curve 110 and the curve 120, the brightness presented inthe first region is identical to the brightness presented in the secondregion when the watching direction is located at the normal viewingangle direction (that is the 0 degree polar viewing angle). Accordingly,the user can see the clear displayed image if the two eyes of the userboth receive the display image in the normal viewing angle direction.Comparatively, at the polar viewing angle P1, the brightness presentedin the first region as shown in the curve 110 is relatively weak whilethe brightness presented in the second region as shown in the curve 120is relatively strong. Therefore, the user who watches the displayedimage at the polar viewing angle P1 can merely see the unclear imageinformation, thereby the privacy protecting effect can be achieved. Itis noted that the user can see the complete image information merelywhen he or she watches the displayed image in the normal viewing angledirection and the user who watches the displayed image in the sideviewing angle direction can only see the unclear image information.Therefore, the privacy protecting mode can be called as a narrow viewingangle display mode.

Specifically, as presented by the curve 110 and the curve 120, the firstregion and the second region present the same displayed brightness onlywhen the polar viewing angle is 0 degree. Nevertheless, practically, thepolar viewing angle that the user watches the image displayed by thedisplay panel in the normal viewing angle direction may be located atthe range from the angle P2 to the angle P3, such as the angle includingthe 0 degree normal viewing angle by ±5 degrees owing that the two eyesof the user are separated from each other by a distance. That is to say,the two eyes of the user located in the normal viewing angle directionsee the image presented by the LCD panel at the angles adjacent to thenormal viewing angle rather than right at the normal viewing angle inthe real circumstance. In the meantime, the brightness received by thetwo eyes of the user differs from each other so that the user located inthe normal viewing angle direction may feel giddy when watching thedisplayed image. In summary, the privacy protecting mode, i.e. thenarrow viewing angle display mode, though prevents from the reveal ofthe personal information, causes uncomfortable feeling of the user inthe normal viewing angle direction.

SUMMARY OF THE INVENTION

The invention provides an LCD panel having privacy protecting effect andfavorable display quality.

The invention provides another LCD panel having privacy protectingeffect and favorable display quality.

For describing the scope of the invention in detail, an LCD paneldivided into at least one first region and at least one second region isprovided. The first region and the second region respectively have aplurality of sub-pixels arranged in an array, and each of the sub-pixelshas a first display area, a second display area and a compensationdisplay area. The first display area provides a first main alignmentvector. The second display area provides a second main alignment vector,and a direction of the first main alignment vector is opposite to adirection of the second main alignment vector. A cell gap of thecompensation display area is substantially greater than a cell gap ofthe first display area and also substantially greater than a cell gap ofthe second display area. Driving voltages of the first display areas inthe first region are substantially greater than driving voltages of thesecond display areas in the first region, driving voltages of the firstdisplay areas in the second region are substantially smaller thandriving voltages of the second display areas in the second region, andall the compensation display areas in the first region and the secondregion are enabled when the LCD panel states in a narrow viewing angledisplay mode.

Another LCD panel is provided in the invention and the LCD panelincludes at least one first region and at least one second region,wherein the first region and the second region respectively have aplurality of sub-pixels. Each of the sub-pixels includes a first displayarea and a second display area. The first display area is divided into aplurality of first alignment areas by a first horizontal baseline and afirst vertical baseline, the first alignment areas respectively have aliquid crystal alignment, and the liquid crystal alignments of the firstalignment areas are different from one another. The second display areais divided into a plurality of second alignment areas by a secondhorizontal baseline and a second vertical baseline, the second alignmentareas respectively have a liquid crystal alignment, and the liquidcrystal alignments of the second alignment areas are different from oneanother. A first driving voltage of the first display areas in the firstregion is substantially greater than a second driving voltage of thefirst display areas in the second region, and the second driving voltageis substantially greater than 0 when the LCD panel displays a firstnormal viewing brightness under a narrow viewing angle mode.

In view of the above, the LCD panel according to the invention improvesthe problem of giddy feeling of the user when the user watches the imagedisplayed by the LCD panel under the narrow viewing angle display modein the normal viewing angle direction by configuring the compensationdisplay area or modulating the brightness of the display areas and theLCD panel according to the invention also provides desirable privacyprotecting effect.

In order to make the aforementioned and other features and advantages ofthe invention more comprehensible, embodiments accompanying figures aredescribed in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide further understanding,and are incorporated in and constitute a part of this specification. Thedrawings illustrate exemplary embodiments and, together with thedescription, serve to explain the principles of the disclosure.

FIG. 1 shows the relationship between the displayed brightness presentedby a conventional LCD panel and the corresponding polar viewing angleswhen the LCD panel is watched at variant polar viewing angles along thehorizontal axis direction.

FIG. 2, FIG. 13, FIG. 19, and FIG. 21 are schematic diagrams of LCDpanels according to embodiments of the invention.

FIG. 3A and FIG. 3B are schematic diagrams of the first pixel electrodesaccording to embodiments of the invention.

FIG. 4A and FIG. 4B are schematic diagrams of the second pixelelectrodes according to embodiments of the invention.

FIG. 5, FIG. 14A, FIG. 14B, FIG. 15A, and FIG. 15B are schematicdiagrams of the third pixel electrodes according to embodiments of theinvention.

FIG. 6A, FIG. 6B, FIG. 16, and FIG. 22A are schematic diagrams of LCDpanels under the wide viewing angle display mode according toembodiments of the invention.

FIG. 7, FIG. 17, and FIG. 22B are schematic diagrams of LCD panels underthe narrow viewing angle display mode according to embodiments of theinvention.

FIG. 8 is a schematic cross-sectional view of the sub-pixel taken alongthe sectioning line A-A′ of FIG. 2.

FIG. 9A and FIG. 18A shows the brightness distribution presented by theenabled different display areas of each sub-pixel in the first regionwhen the LCD panel states in the narrow viewing angle display modeaccording to embodiments of the invention.

FIG. 9B and FIG. 18B show the brightness distribution presented by theenabled different display areas of each sub-pixel in the second regionwhen the LCD panel states in the narrow viewing angle display modeaccording to embodiments of the invention.

FIG. 10 shows the relationship of the first main alignment vector, thesecond main alignment vector and the watching direction of the useraccording to an embodiment of the invention.

FIG. 11 illustrates the brightness distribution of a portion of the LCDpanel under the narrow viewing angle display mode at variant azimuthviewing angles Φ when the LCD panel is watched at the polar viewingangle θ=60°.

FIG. 12 illustrates one of the driving methods used in driving the LCDpanel according to an embodiment of the invention when the LCD panel ispredetermined to state in the wide viewing angle display mode (or thenarrow viewing angle display mode).

FIG. 20 is a schematic cross-sectional view of the sub-pixel taken alongthe sectioning line A-A′ and the sectioning line B-B′ of FIG. 19.

DESCRIPTION OF EMBODIMENTS

In the LCD panel of the invention, each of the sub-pixels has a firstdisplay area and a second display area, and further selectively has acompensation display area. Namely, each of the sub-pixels is dividedinto a plurality of display areas. Furthermore, a main alignment vectorof the first display area has a direction opposite to a direction of amain alignment vector of the second display area, wherein therepresented “main alignment vector” in the disclosure means thequantification of the alignment force subjected by the liquid crystallayer in each display area of the LCD panel. Generally, the value andthe direction of the alignment force subjected by the liquid crystallayer in each display area determines the presented brightnessdistribution of the display area under variant polar viewing angles andvariant azimuth viewing angles. Accordingly, the opposite directions ofthe main alignment vectors provided respectively by the first displayarea and the second display area represent that the brightnessdistributions presented by the first display area and the second displayarea are not identical to each other under variant polar viewing anglesand variant azimuth viewing angles. For example, the brightnessdistributions present by the first display area and the second displayarea can be shown as the curve 110 and the curve 120 in FIG. 1,respectively.

The first display area and the second display area of each sub-pixel areenabled (i.e. are lighted) when the LCD panel states in the wide viewingangle display mode, and thus the brightness at different viewing anglespresented by the first display area and the second display area in eachsub-pixel can compensate mutually to facilitate the wide viewing anglecharacteristic of each sub-pixel and achieve the wide viewing angledisplay effect of the LCD panel in the invention.

The LCD panel is divided into at least one first region and at least onesecond region when the LCD panel according to the invention states inthe narrow viewing angle display mode. In the meantime, driving voltagesof the first display areas in the first region are substantially greaterthan driving voltages of the second display areas in the first region,and driving voltages of the first display areas in the second region aresubstantially smaller than driving voltages of the second display areasin the second region. In an example, the first display area of thesub-pixel in the first region can be enabled while the second displayarea of the sub-pixel in the first region is disabled, and with respectto the sub-pixel in the second region, the second display area isenabled while the first display area is disabled. Accordingly, thebrightness distributions under variant polar viewing angles and variantazimuth angles are different in the first region and the second regionof the LCD panel. Based on such circumstance, the brightness presentedby the first region or the second region is different from thepredetermined displayed brightness when the LCD panel is watched at theside viewing angles so that the user located in the side viewing angledirection can not see the correct image, which facilitates the privacyprotecting effect.

Particularly, under the configuration of the compensation display areas,the compensation display areas of all the sub-pixels are enabled whenthe LCD states in the narrow viewing angle display mode so as tocompensate the brightness at the angles adjacent the normal viewingangle presented by each sub-pixel in the first region and the secondregion. Alternately, the display area in each sub-pixel which ispredetermined to be disabled can display a darker (faint) brightnesswhen the LCD panel is configured without the compensation display area.Herein, the brightness at the viewing angle adjacent the normal viewingangle presented by the first region and the second region in the LCDpanel can be substantially identical to the predetermined displayedbrightness so that the problem that the user located in the normalviewing angle direction feels giddy when watching the image displayed bythe LCD panel under the narrow viewing angle display mode is mitigated.

It is noted that the cell gap of the compensation display area issubstantially greater than the cell gap of the first display area andalso substantially greater than the cell gap of the second display areain the LCD panel according to the invention, such that the brightnessdistribution provided by the compensation display area is moreconcentrated around the normal viewing angle (i.e. concentrated at thesmall side viewing angles) than that provided by the first display areaand the second display area. As such, the brightness at the viewingangle adjacent the normal viewing angle can be compensated by theenabled compensation display area so that the problem that the userlocated in the normal viewing angle direction feels giddy when watchingthe image displayed by the LCD panel under the narrow viewing angledisplay mode is mitigated. On the other hand, the brightnessdistribution presented by the compensation display area is concentratedaround the normal viewing angle so that the brightness provided by thecompensation display area would not negatively influence on the privacyprotecting effect of the LCD panel.

In light of the foregoing, the LCD panel according to the inventionimproves the problem of giddy feeling of the user when the user watchesthe image displayed by the LCD panel under the narrow viewing angledisplay mode in the normal viewing angle direction by configuring thecompensation display area or modulating the brightness of the displayareas and the LCD panel according to the invention also providesdesirable privacy protecting effect.

The features of the invention are further described in the followingaccompanying with the drawings.

The First Embodiment

FIG. 2 is a schematic view of an LCD panel according to an embodiment ofthe invention. Referring to FIG. 2, an LCD panel 200 in this embodimentis divided into at least one first region R1 and at least one secondregion R2. For instance, the LCD panel 200 according to the presentembodiment can be divided into a plurality of region unit U arranged inan array. Each region unit U includes two first regions R1 and twosecond regions R2, wherein the first regions R1 and the second regionsR2 are alternatively arranged in the x direction and in the y direction.

Each of the first regions R1 and each of the second regions R2respectively have a plurality of sub-pixels 210 arranged in an array.The color displayed by the sub-pixels 210 can include red, green, blue,yellow, and the like, but the invention is not limited thereto. Each ofthe sub-pixels 210 has a first display area r1, a second display arear2, and a compensation display area r3. The first display area r1provides the first main alignment vector D1 and the second display arear2 provides a second main alignment vector D2, wherein a direction ofthe first main alignment vector D1 is opposite to a direction of thesecond main alignment vector D2.

Specifically, the first display area r1, the second display r2, and thecompensation display area r3 according to the present embodiment can bedefined by the first pixel electrode 212, the second pixel electrode214, and the third pixel electrode 216 of each sub-pixel 210.

FIG. 3A is a schematic diagram of the first pixel electrode according toan embodiment of the invention. Referring to FIG. 3A, the first pixelelectrode 212 in the present embodiment can have a first alignment areaK1 and a second alignment area K2 and the vector sum of a firstalignment vector d1 of the first alignment area K1 and a secondalignment vector d2 of the second alignment area K2 constructs the firstmain alignment vector D1. It is noted that the alignment vectordescribed in the disclosure means the vector transformed from thealignment ability provided by one single alignment area, wherein thedirection and the value of each alignment vector are related to thestructural design of the alignment area and the area thereof.

Referring to FIG. 3A, the first pixel electrode 212 in the presentembodiment can specifically include two first main trunk portions 212 aand 212 b and a plurality of first branch portions 212 c and 212 dconnected with the first main trunk portion 212 a or the first maintrunk portion 212 b, wherein the extending direction of the first maintrunk portion 212 a is substantially parallel to the x direction and theextending direction of the first main trunk portion 212 b issubstantially parallel to the y direction. The first main trunk portion212 a is substantially parallel to the x direction divides the firstpixel electrode 212 into the first alignment area K1 and the secondalignment area K2. The first branch portions 212 c are disposed in thefirst alignment area K1 and are intersected with the first main trunkportion 212 a or the first main trunk 212 b by about 45 degrees. Thefirst branch portions 212 d are disposed in the second alignment area K2and are intersected with the first main trunk portion 212 a or thesecond main trunk 212 b by about 45 degrees. In addition, the firstbranch portions 212 c and the first branch portions 212 d are notparallel to each other. According to the x direction depicted in FIG.3A, the direction of the first alignment vector d1 provided by the firstbranch portions 212 c in the first alignment area K1 is intersected withthe x direction by about 315°. The direction of the second alignmentvector d2 provided by the first branch portions 212 d in the secondalignment area K2 is intersected with the x direction by about 45°. As awhole, the direction of the vector sum (i.e. the first main alignmentvector D1) of the first alignment vector d1 and the second alignmentvector d2 directs toward the +x direction.

However, the invention is not limited thereto. The first pixel electrode212 can be designed as that shown in FIG. 3B, wherein a fifth alignmentarea K5 and a sixth alignment area K6 can be further demarked in thefirst pixel electrode 212 by the first main trunk portions 212 a and 212b in addition to the first alignment area K1 and the second alignmentarea k2. Herein, the first alignment vector d1 of the first alignmentarea K1, the second alignment vector d2 of the second alignment area K2,a fifth alignment vector d5 of the fifth alignment area K5, and a sixthalignment vector d6 of the sixth alignment area K6 together constructthe first main alignment vector D1.

In addition, the first pixel electrode 212 in the present embodiment canfurther include a plurality of first branch portions 212 e and 212 fconnected with the first main trunk portion 212 a or the first maintrunk portion 212 b, wherein the first branch portions 212 e are locatedin the fifth alignment area K5 and the first branch portions 212 f arelocated in the sixth alignment area K6. The direction of the fifthalignment vector d5 provided by the first branch portions 212 e in thefifth alignment area K5 is intersected with the x direction by about225°. The direction of the sixth alignment vector d6 provided by thefirst branch portions 212 f in the sixth alignment area K6 isintersected with the x direction by about 135°. As a whole, thedirection of the vector sum (i.e. the first main alignment vector D1) ofthe first alignment vector d1, the second alignment vector d2, the fifthalignment vector d5, and the sixth alignment vector d6 directs towardthe +x direction.

FIG. 4A is a schematic diagram of the second pixel electrode accordingto an embodiment of the invention. Referring to FIG. 4A, the secondpixel electrode 214 in the present embodiment can have a third alignmentarea K3 and a fourth alignment area K4 and a vector sum of a thirdalignment vector d3 of the third alignment area K3 and a fourthalignment vector d4 of the fourth alignment area K4 constructs thesecond main alignment vector D2.

Referring to FIG. 4A, the second pixel electrode 214 in the presentembodiment can specifically include two second main trunk portions 214 aand 214 b and a plurality of second branch portions 214 c and 214 dconnected with the second main trunk portion 214 a or the second maintrunk portion 214 b, wherein the extending direction of the second maintrunk portion 214 a is substantially parallel to the x direction and theextending direction of the second main trunk portion 214 b issubstantially parallel to the y direction. The second main trunk portion214 a is substantially parallel to the x direction divides the secondpixel electrode 214 into the third alignment area K3 and the fourthalignment area K4. The second branch portions 214 c are disposed in thethird alignment area K3 and are intersected with the second main trunkportion 214 a or the second main trunk 214 b by about 45 degrees. Thesecond branch portions 214 d are disposed in the fourth alignment areaK4 and are intersected with the second main trunk portion 214 a or thesecond main trunk 214 b by about 45 degrees. In addition, the secondbranch portions 214 c and the second branch portions 214 d are notparallel to each other.

According to the x direction depicted in FIG. 4A, the direction of thethird alignment vector d3 provided by the second branch portion 214 c inthe third alignment area K3 is intersected with the x direction by about225°. The direction of the fourth alignment vector d4 provided by thesecond branch portion 214 d in the fourth alignment area K4 isintersected with the x direction by about 135°. As a whole, thedirection of the vector sum (i.e. the second main alignment vector D2)of the third alignment vector d3 and the fourth alignment vector d4directs toward the −x direction.

However, the invention is not limited thereto. The second pixelelectrode 214 can be designed as that shown in FIG. 4B, wherein aseventh alignment area K7 and an eighth alignment area K8 can be furtherdemarked in the second pixel electrode 214 by the second main trunkportions 214 a and 214 b in addition to the third alignment area K3 andthe fourth alignment area k4. Herein, the third alignment vector d3 ofthe third alignment area K3, the fourth alignment vector d4 of thefourth alignment area K4, a seventh alignment vector d7 of the seventhalignment area K7, and an eighth alignment vector d8 of the eighthalignment area K8 together construct the second main alignment vectorD2.

In addition, the second pixel electrode 214 in the present embodimentcan further include a plurality of second branch portions 214 e and 214f connected with the second main trunk portion 214 a or the second maintrunk portion 214 b, wherein the second branch portions 214 e arelocated in the seventh alignment area K7 and the second branch portions214 f are located in the eighth alignment area K8. The direction of theseventh alignment vector d7 provided by the second branch portion 214 ein the seventh alignment area K7 is intersected with the x direction byabout 315°. The direction of the eighth alignment vector d8 provided bythe second branch portion 214 f in the eighth alignment area K8 isintersected with the x direction by about 45°. As a whole, the directionof the vector sum (i.e. the second main alignment vector D2) of thethird alignment vector d3, the fourth alignment vector d4, the seventhvector d7, and the eighth vector d8 directs toward the −x direction.

It is noted that the amount of the alignment areas configured in thepixel electrodes 212 and 214 is not particularly limited and merely thetotal alignment ability provided by the electrode constructs the mainalignment vector D1 or D2 can the electrode be used as the pixelelectrode in the sub-pixel 210 depicted in FIG. 2. In addition, theachievement of the alignment ability of the first main alignment vectorD1 is not limited by using the design of the pixel electrode 212 in theinvention. In other embodiments, the alignment structures or otherstructure design can be used in the sub-pixel 210 for having therequired alignment ability.

FIG. 5 is a schematic diagram of the third pixel electrode according toan embodiment of the invention. Referring to FIG. 5, the third pixelelectrode 216 can have a first compensation alignment area J1, a secondcompensation alignment area J2, a third compensation alignment area J3,and a fourth compensation alignment area J4, and a vector sum of a firstcompensation alignment vector e1 of the first compensation alignmentarea J1, a second compensation alignment vector e2 of the secondcompensation alignment area J2, a third compensation alignment vector e3of the third compensation alignment area J3, and a fourth compensationalignment vector e4 of the fourth compensation alignment area J4constructs the main compensation vector D3.

Referring to FIG. 5, the third pixel electrode 216 in the presentembodiment can specifically include two third main trunk portions 216 aand 216 b and a plurality of third branch portions 216 c, 216 d, 216 e,and 216 f connected with the third main trunk portion 216 a or the thirdmain trunk portion 216 b, wherein the extending direction of the thirdmain trunk portion 216 a is substantially parallel to the x directionand the extending direction of the third main trunk portion 216 b issubstantially parallel to the y direction. The third main trunk portions216 a and 216 b divide the third pixel electrode 216 into the firstcompensation alignment area J1, the second compensation alignment areaJ2, the third compensation alignment area J4 having substantial the samearea. The third branch portions 216 c are located in the firstcompensation alignment area J1 and the direction of the firstcompensation alignment vector e1 provided in the first compensationalignment area J1 is intersected with the x direction by about 225°. Thethird branch portions 216 d are located in the second compensationalignment area J2 and the direction of the second compensation alignmentvector e2 provided in the second compensation alignment area J2 isintersected with the x direction by about 315°. The third branchportions 216 e are located in the third compensation alignment area J3and the direction of the third compensation alignment vector e3 providedin the third compensation alignment area J3 is intersected with the xdirection by about 45°. The third branch portions 216 f are located inthe fourth compensation alignment area J4 and the direction of thefourth compensation alignment vector e4 provided in the fourthcompensation alignment area J4 is intersected with the x direction byabout 135°. In the present embodiment, the vector sum (i.e. the maincompensation alignment D3) of the first compensation alignment vectore1, the second compensation alignment vector e2, the third compensationalignment vector e3, and the fourth compensation alignment vector e4 canbe substantially zero. However, the present invention does not limitedto the embodiment. According to another embodiment, the maincompensation alignment vector D3 can be other vector. It is noted thatthe alignment vectors can be achieved by various methods according tothe invention and each pixel electrode is not limited to the aforesaidembodiments. That is, the design of the pixel electrodes can be modifiedaccording to the actual requirement and the invention is not restrictedthereto.

FIG. 6A is a schematic view of an LCD panel under the wide viewing angledisplay mode according to the first embodiment of the invention.Referring to FIG. 6, each of the sub-pixels 210 has a first display arear1, a second display area r2, and a compensation display area r3 whichare driven independently. All the first display areas r1 and all thesecond display areas r2 of the sub-pixels 210 in the first region R1 andthe second region R2 are enabled when the LCD panel 200 states in thewide viewing angle display mode. Furthermore, the compensation displayareas r3 of all the sub-pixels 210 located in the first region R1 andthe second region R2 are enabled. Herein, the first display area r1, thesecond display area r2, and the compensation display area r3 in eachsub-pixel 210 provide the displayed brightness and the brightnessdisplayed by each sub-pixel 210 at variant viewing angles complies withthe predetermined displayed brightness because the first main alignmentvector D1 of the first display area r1 differs from the second mainalignment vector D2 of the second display area r2, such that the LCDpanel 200 has the wide viewing angle display characteristic. However,the invention is not limited thereto. As shown in FIG. 6B, thecompensation display areas r3 of all the sub-pixels 210 in the firstregion R1 and the second region R2 can be disabled when the LCD panel200 states in the wide viewing angle display mode. Herein, the LCD panel200 still has the wide viewing angle display characteristic while thebrightness presented by the LCD panel 200 at variant viewing angles isslightly reduced.

FIG. 7 is a schematic view of an LCD panel under the narrow viewingangle display mode according to the first embodiment of the invention.Referring to FIG. 7, the first region R1 and the second region R2 areoperated by different methods when the LCD panel 200 states in thenarrow viewing angle display mode. Specifically, driving voltages of thefirst display areas r1 in the first region R1 are substantially greaterthan driving voltages of the second display areas r2 in the first regionR1 and driving voltages of the first display areas r1 in the secondregion R2 are substantially smaller than driving voltages of the seconddisplay areas r2 in the second region R2 when the LCD panel 200 statesin the narrow viewing angle display mode. For instance, in the firstregion R1, the first display area r1 of each sub-pixel 210 is enabledand the second display area r2 of each sub-pixel 210 is disabled. Inaddition, in the second region R2, the first display area r1 of eachsub-pixel 210 is disabled and the second display area r2 of eachsub-pixel 210 is enabled. The first main alignment vector D1 of thefirst display area r1 has the direction opposite to the direction of thesecond main alignment vector D2 of the second display area r2, such thatthe brightness distributions in the first region R1 and the secondregion R2 of the LCD panel 200 are different. Based on suchcircumstance, the user located in the side viewing angle direction cannot see the correct image owing that the brightness distributionpresented by the LCD panel 200 at the side viewing angles do not complywith the predetermined displayed brightness distribution, whichfacilitates the privacy protecting effect.

It is noted that the compensation display areas r3 in all of thesub-pixels 210 are enabled for compensating the brightness presented bythe first region R1 and the second region R2 at the viewing anglesadjacent to the normal viewing angle when the LCD panel 200 of thepresent embodiment states in the narrow viewing angle display mode, suchthat the brightness presented at the viewing angles adjacent to thenormal view angle (i.e. the angles ranging between about ±5° polarviewing angles) can be close to the predetermined displayed brightnessto mitigate the giddy feeling of the user watching the displayed imagein the normal viewing angle direction. In addition, as shown in FIG. 8which is the cross-sectional view of the sub-pixel 210 taken along thesectioning line A-A′ of FIG. 2, the cell gap G3 of the compensationdisplay area r3 in the LCD panel 200 according to the present embodimentis substantially greater than the cell gap G1 of the first display arear1 and the cell gap G2 of the second display area r2. Accordingly, thebrightness distribution provided by the compensation display area r3 ismore concentrated around the normal viewing angle and the small polarviewing angles than those provided by the first display area r1 and thesecond display area r2. The compensation display areas r3 can providethe compensation function for compensating the brightness presented inthe first region R1 and the second region R2 at the viewing anglesadjacent to the normal viewing angle, such that the brightness presentedby the first region R1 and the second region R2 at the small sideviewing angles of the LCD panel 200 can be close to the predetermineddisplayed brightness to mitigate the giddy feeling of the user watchingthe displayed image in the normal viewing angle direction. In thepresent embodiment, the cell gap G3 of the compensation display area r3is substantially 7 μm while the cell gap G1 of the first display area r1and the cell gap G2 of the second display area r2 are substantially 3.5μm, but the invention is not limited thereto.

In the present embodiment, the LCD panel 200 can provide desirabledisplay quality to the user in the normal viewing angle direction underthe narrow viewing angle display mode by lighting the compensationdisplay areas r3 and the compensation is further depicted in thefollowing.

FIG. 9A shows the brightness distribution presented by the enableddifferent display areas of each sub-pixel in the first region R1 whenthe LCD panel states in the narrow viewing angle display mode accordingto an embodiment of the invention. FIG. 9B shows the brightnessdistribution presented by the enabled different display areas of eachsub-pixel in the second region R2 when the LCD panel states in thenarrow viewing angle display mode according to an embodiment of theinvention. Referring to FIG. 9A and FIG. 9B simultaneously, therelationship between the polar viewing angle θ and the brightnesspresented by the first display area r1 of the sub-pixel 210 is shown inthe drawing (a) of FIG. 9A. The relationship between the polar viewingangle θ and the brightness presented by the second display area r2 ofthe sub-pixel 210 is shown in the drawing (a) of FIG. 9B. Therelationships between the polar viewing angle 6 and the brightnesspresented by the compensation display areas r3 in the first region R1and the second region R2 are shown in the drawing (b) of FIG. 9A and inthe drawing (b) of FIG. 9B, respectively.

If the compensation display areas r3 are not disposed in the sub-pixels210 in the first region R1 and the second region R2, the right eye ofthe user (watching the displayed image at the about 5° polar viewingangle) can receive relative weak brightness presented in the firstregion R1 and relative strong brightness presented in the second regionR2. At the same time, the left eye of the user (watching the displayedimage at the about −5° polar viewing angle) can receive relative strongbrightness presented in the first region R1 and relative weak brightnesspresented in the second region R2. As such, the two eyes of the userreceive different brightness presented in the same region and the brainof the user fails to determine the actual brightness presented by thefirst region R1 and the second region R2, which makes the user giddy.

Nevertheless, the LCD panel 200 of the present embodiment has thecompensation display areas r3. Under the narrow viewing angle displaymode, the distribution between the polar viewing angle θ and thebrightness presented by the first region R1 can be the overlap of thedistribution between the polar viewing angle θ and the brightnesspresented by the first display area r1 and the distribution between thepolar viewing angle θ and the brightness presented by the compensationdisplay area r3 as shown in the drawing (c) of FIG. 9A. Similarly, thedistribution between the polar viewing angle θ and the brightnesspresented by the second region R2 can be the overlap of the distributionbetween the polar viewing angle θ and the brightness presented by thesecond display area r2 and the distribution between the polar viewingangle θ and the brightness presented by the compensation display area r3as shown in the drawing (c) of FIG. 9B. As shown in the drawing (c) ofFIG. 9A and the drawing (c) of FIG. 9B, owing that the sub-pixels 210 inthe first region R1 and the second region R2 have the compensationdisplay areas r3, the difference of the brightness from the first regionR1 or the second region R2 received by the two eyes of the users can bereduced when all of the compensation display areas r3 are enabled underthe narrow viewing angle display mode, which mitigates the problem ofgiddy feeling of the user watching the displayed image in the normalviewing angle direction. In addition, the cell gap G3 of thecompensation display area r3 is substantially greater than the cell gapG1 of the first display area r1 and also substantially greater than thecell gap G2 of the second display area r2. Accordingly, the brightnessdistribution provided by the compensation display area r3 is moreconcentrated around the normal viewing angle and the small polar viewingangle than those provided by the first display area r1 and the seconddisplay area r2. The compensation display areas r3 can compensate thebrightness presented by the first region R1 and the second region R2 atthe angles adjacent to the normal viewing angle without significantlyinfluencing on the brightness presented by the first region R1 and thesecond region R2 at larger polar viewing angles (such as the pointmarked by X and Y in FIG. 9A and FIG. 9B) so that the brightnesspresented at the larger polar viewing angles X and Y can be different inthe first region R1 and the second region R2. Thereby, the LCD panel 200can have favorable privacy protecting function.

Specifically, the privacy protecting function of the LCD panel 200 underthe narrow viewing angle display mode can be modulated by theconfiguring area ratio of the first display area r1 (or the seconddisplay area r2) and the compensation display area r3. The resultslisted in table 1 are taken as an example.

TABLE 1 The polar viewing angle 0 (°) along the horizontal axisdirection (0° azimuth viewing The ratio of the brightness in the firstregion angle or 180° azimuth angle) R1 and the brightness in the secondregion R2 5 45 60 No compensation display areas 1.35 47.38 427.14 Thearea ratio of the first display area 4:1 1.20 17.47 391.78 (or thesecond display area) and the 2:1 1.14 11.00 329.43 compensation displayarea 1:1 1.09 6.60 251.61

The ratio of the brightness in the first region R1 and the brightness inthe second region R2 at the about 5° polar viewing angle is about 1.35when the LCD panel 200 does not have the compensation display areas. Theratio of the brightness in the first region R1 and the brightness in thesecond region R2 at the about 5° polar viewing angle is reduced to about1.09 when the area ratio of the first display area r1 (or the seconddisplay area r2) and the compensation display area r3 is enhanced toabout 1:1, which means the brightness in the first region R1 is quiteclose to the brightness in the second region R2. Therefore, the userwatching the image displayed by the LCD panel 200 under the privacyprotecting mode does not feel giddy easily when the area ratio of thefirst display area r1 (or the second display area r2) and thecompensation display area r3 is enhanced to about 1:1. The ratio of thebrightness in the first region R1 and the brightness in the secondregion R2 at the about 60° polar viewing angle is about 251.61 when thearea ratio of the first display area r1 (or the second display area r2)and the compensation display area r3 is enhanced to about 1:1, whichmeans the brightness in the first region R1 is quite different from thebrightness in the second region R2 at the large polar viewing angle. Inother words, the LCD panel 200 provides favorable privacy protectingquality when being watched at large polar viewing angle.

FIG. 10 shows the relationship of the first main alignment vector D1,the second main alignment vector D2, and the watching direction F1 ofthe user S. FIG. 11 illustrates the brightness distribution presented bya portion of the LCD panel under the narrow viewing angle display modeat variant azimuth viewing angles Φ when the LCD panel is watched at thepolar viewing angle θ=60°. Referring to FIG. 10, the LCD panel 200 isassumed to be located at the x-y plane, and the normal direction of theLCD panel 200 is the z direction. The projection of the first mainalignment vector D1 on the x-y plane directs towards the +x directionand the first main alignment vector D1 intersects with the z axis byabout 60°. The projection of the second main alignment vector D2 on thex-y plane directs towards the −x direction and the second main alignmentvector D2 intersects with the z axis by about 60°. Herein, if the user Swatches the image displayed by the LCD panel 200 under the narrowviewing angle display mode at the polar viewing angle θ=60° and theazimuth viewing angle Φ=0°, the watching direction F1 of the user S issubstantially parallel to the first main alignment vector D1 provided bythe first display area r1 in the first region R1 and thus theretardation provided by the liquid crystals in the first display area r1of the first region R1 is 0 for the user S. As such, the user S watchingthe LCD panel 200 in the watching direction F1 (polar viewing angleθ=60° and the azimuth viewing angle Φ=0° sees the darker first regionR1. Similarly, if the user S watches the image displayed by the LCDpanel 200 under the narrow viewing angle display mode at the polarviewing angle θ=60° and the azimuth viewing angle Φ=0°, the watchingdirection F1 of the user S is not parallel to the second main alignmentvector D2 provided by the second display area r2 in the second region R2and thus the retardation provided by the liquid crystals in the seconddisplay area r2 of the second region R2 is not 0 for the user S. Theuser S watching the LCD panel 200 in the watching direction F1 sees thebrighter second region R2. Therefore, the LCD panel 200 provides thenoise image having uneven brightness in different regions to the user Slocated in the side viewing angle direction (as shown in the drawing (b)of FIG. 11), so that the privacy protecting effect is achieved. The LCDpanel 200 also provides the noise image having uneven brightness indifferent regions to the user S located in other side viewing angledirections (as shown in the drawings (c) to (g) of FIG. 11), so that theprivacy protecting effect is achieved.

The layout of the sub-pixel disposed in the LCD panel according to thepresent embodiment is described in detail in the following, wherein thelayout designs of the sub-pixels 210 in the first region R1 and thesecond region R2 can be different and are respectively depicted in thefollowing. Referring to the drawing (a) of FIG. 12, each of thesub-pixels 210 located in the first region R1 can further include afirst scan line SL1, a second scan line SL2, a common line CL, a dataline DL, a first active device T1, a second active device T2, and athird active device T3 in addition to the first pixel electrode 212, thesecond pixel electrode 214, and the third pixel electrode 216. The dataline DL intersects with the first scan line SL1, the second scan lineSL2, and the common line CL. The first active device T1 is driven by thefirst scan line SL1, and connected with the data line DL, the firstpixel electrode 212, and the second pixel electrode 214 to controlwhether the first pixel electrode 212 and the second electrode 214 areelectrically connected to the data line DL. The second active device T2is driven by the second scan line SL2, and connected with the secondpixel electrode 214 and the common line CL to control whether the secondpixel electrode 214 is electrically connected to the common line CL. Thethird active device T3 is driven by the second scan line SL2, andconnected with the data line DL and the third pixel electrode 216 tocontrol whether the third pixel electrode 216 is electrically connectedto the data line DL.

Referring to the drawing (b) of FIG. 12, each of the sub-pixels 210located in the second region R2 can further include a first scan lineSL1, a second scan line SL2, a common line CL, a data line DL, a firstactive device T1, a second active device T2, and a third active deviceT3 in addition to the first pixel electrode 212, the second pixelelectrode 214, and the third pixel electrode 216. The data line DLintersects with the first scan line SL1, the second scan line SL2, andthe common line CL. The first active device T1 is driven by the firstscan line SL1, and connected with the data line DL, the first pixelelectrode 212, and the second pixel electrode 214 to control whether thefirst pixel electrode 212 and the second electrode 214 are electricallyconnected to the data line DL. The second active device T2 is driven bythe second scan line SL2, and connected with the first pixel electrode212 and the common line CL to control whether the first pixel electrode212 is electrically connected to the common line CL. The third activedevice T3 is driven by the second scan line SL2, and connected with thedata line DL and the third pixel electrode 216 to control whether thethird pixel electrode 216 is electrically connected to the data line DL.In short, each sub-pixel 210 located in the second region R2 is similarto each sub-pixel 210 located in the first region R1, except that therelative position of the first pixel electrode 212 and the second pixelelectrode 214 in the sub-pixel 210 of the second region R2 is arrangedin the way opposite to the relative position of the first pixelelectrode 212 and the second pixel electrode 214 in the sub-pixel 210 ofthe first region R1.

It is noted that the cell gap corresponding to the third pixel electrode216 in the present embodiment can be greater than the cell gapscorresponding to the first pixel electrode 212 and the second pixelelectrode 214 for enhancing the compensation effect provided by thecompensation display area r3 corresponding to the third pixel electrode216. For example, the cell gaps corresponding to the first pixelelectrode 212 and the second pixel electrode 214 can be about 3.5 μm andthe cell gap corresponding to the third pixel electrode 216 can be about7 μm. The brightness distribution provided by the compensation displayareas r3 at the variant polar viewing angles can be concentrated aroundthe viewing angles adjacent to the normal viewing angle, such that thebrightness presented by the first region R1 and the second region R2 ofthe LCD panel 200 at the small side viewing angles can be close to thepredetermined displayed brightness to mitigate the giddy feeling of theuser watching the displayed image in the normal viewing angle direction.

The second scan line SL2 can be turned on first when the LCD panel 200in the present embodiment states in the wide viewing angle display modeand the data line DL can apply a driving voltage to the third pixelelectrode 216. Accordingly, the compensation display area r3 in thefirst region R1 and the second region R2 can present a bright image. Inaddition, the second pixel electrode 214 located in the first region R1and the first pixel electrode 212 located in the second region R2 areelectrically connected to the common line CL due to the turning on ofthe second active device T2 by the second scan line SL2. Therefore, thesecond display areas r2 of the sub-pixels 210 in the first region R1 andthe first display areas r1 of the sub-pixels 210 in the second region R2all display the dark image. Next, the first scan line SL1 is turned onand the data line DL applies a predetermined voltage (i.e. the displayedvoltage) to the first pixel electrode 212 and the second pixel electrode214. Herein, the first display areas r1, the second display areas r2,and the compensation display areas r3 in either the first region R1 orthe second region R2 are enabled and lighted to display the image.Thereby, the LCD panel 200 can have wide viewing angle displaycharacteristic. In an alternate embodiment, when the second scan lineSL2 is turned on first, the data line DL can apply a driving voltage ofabout 0V or a dark voltage to the third pixel electrode 216. Thus, thecompensation display areas r3 in either the first region R1 or thesecond region R2 are disabled and merely the first display areas r1 andthe second display areas r2 in the first region R1 and the second regionR2 are enabled and lighted to display the image.

When the LCD panel 200 in the present embodiment states in the narrowviewing angle display mode, the first scan line SL1 can be turned onfirst and the data line DL can apply a predetermined driving voltage(such as the corresponding displayed voltage) to the first pixelelectrode 212 and the second pixel electrode 214. In the meantime, thefirst display areas r1 and the second display areas r2 located in boththe first region R1 and the second region R2 are enabled and lighted.Next, the second scan line SL2 is turned on and the data line DL appliesanother predetermined voltage (i.e. another displayed voltage) to thethird pixel electrode 216. Accordingly, the compensation display areasr3 in either the first region R1 or the second region R2 are enabled andlighted to display the image. Simultaneously, the second active deviceT2 is turned on by the second scan line SL2. In the sub-pixel 210 in thefirst region R1, the second pixel electrode 214 is electricallyconnected to the common line CL and in the sub-pixel 210 in the secondregion R2, the first pixel electrode 212 can be electrically connectedto the common line CL. Therefore, in the sub-pixels 210 located in thefirst region R1, the first display areas r1 and the compensation displayareas r3 are enabled and lighted while the second display areas r2 arenot lighted. In the sub-pixels 210 located in the second region R2, thesecond display areas r2 and the compensation display areas r3 areenabled and lighted while the first display areas r1 are not lighted.Thereby, the LCD panel 200 can display the image having the privacyprotecting characteristic.

It is noted that the driving method described in the above is achievedby configuring two scan lines and one data lines (i.e. the so-called2D1G structure) in the LCD panel 200 for switching between the wideviewing angle display mode and the narrow viewing angle display moderather than by configuring one data line and three scan lines (i.e.so-called 1D3G structure) or by configuring two data lines and two scanlines (i.e. so-called 2G2D structure) in the conventional designs.Accordingly, the LCD panel can have higher aperture ratio and betterlight transmittance in comparison to the conventional LCD panel.

The Second Embodiment

FIG. 13 is a schematic view of an LCD panel according to a secondembodiment of the invention. Referring to FIG. 13, the LCD panel 200A issimilar to the LCD panel 200 of the first embodiment while thecompensation display area r3 of the third pixel electrode in the presentembodiment has the design different from the compensation display arear3 of the first embodiment, and the difference therebetween is describedin the following. It is noted that the components in the presentembodiment the same to those in the first embodiment are not iteratedhere.

The LCD panel 200A in the present embodiment is divided into at leastone first region R1 and at least one second region R2, the first regionR1 and the second region R2 respectively have a plurality of sub-pixels210 arranged in an array, and each of the sub-pixels 210 has the firstdisplay area r1 providing the first main alignment vector D1, the seconddisplay area r2 providing the second main alignment vector D2, and thecompensation display area r3, wherein the directions of the first mainalignment vector D1 and the second main alignment vector D2 are oppositeto each other.

In specific, the cell gap of the compensation display area r3 issubstantially greater than the cell gap of the first display area r1 andalso substantially greater than the cell gap of the second display arear2 according to the present embodiment. Furthermore, the compensationdisplay areas r3 in the first region R1 and the second region R2 providedifferent alignment abilities. The compensation display areas r3 in theregions R1 and R2 are further described in detail in the following.

Referring to FIG. 14A, the third pixel electrode 216 located in thefirst region R1 has a first compensation alignment area I1 and a secondcompensation alignment area 12, and a vector sum (i.e. the maincompensation alignment vector D3′) of a first compensation alignmentvector f1 of the first compensation alignment area I1 and a secondcompensation alignment vector f2 of the second compensation alignmentarea 12 is substantially parallel to the second main alignment vectorD2. In other words, the vector sum (i.e. the main compensation alignmentvector D3′) has the direction opposite to the direction of the firstmain alignment vector D1 of the first display area r1 in the firstregion R1. The main compensation alignment vector D3′ can provide thecompensation effect to the first display area r1 in the first region R1when the LCD panel 200A states in the narrow viewing angle display mode.

The first compensation alignment vector f1 and the second compensationalignment vector f2 provided by the third pixel electrode 216 in thefirst region R1 can be achieved by various ways. For instance, the firstcompensation alignment vector f1 and the second compensation alignmentvector f2 of the third pixel electrode 216 in the first region R1 can beachieved by the pattern design of the third pixel electrode 216 shown inFIG. 14A. In the present embodiment, the third pixel electrode 216 caninclude two third main trunk portions 216 a and 216 b and a plurality ofthird branch portions 216 c and 216 d connected with the third maintrunk portion 216 a or the third main trunk portion 216 b, wherein theextending direction of the third main trunk portion 216 a issubstantially parallel to the x direction and the extending direction ofthe third main trunk portion 216 b is substantially parallel to the ydirection. The third main trunk portion 216 a is substantially parallelto the x direction divides the third pixel electrode 216 into the firstcompensation alignment area I1 and the second compensation alignmentarea 12. The third branch portions 216 c are disposed in the firstcompensation alignment area I1 and intersect with the third main trunkportion 216 a or the third main trunk 216 b by about 45 degrees. Thethird branch portions 216 d are disposed in the second compensationalignment area 12 and intersect with the third main trunk portion 216 aor the third main trunk portion 216 b by about 45 degrees. In addition,the third branch portions 216 c and the third branch portions 216 d arenot parallel to each other.

According to the x direction depicted in FIG. 14A, the direction of thefirst compensation alignment vector f1 provided by the third branchportions 216 c in the first compensation alignment area I1 intersectswith the x direction by about 225°. The direction of the secondcompensation alignment vector f2 provided by the third branch portion216 d in the second compensation alignment area 12 intersects with the xdirection by about 135°. Accordingly, the direction of the vector sum(i.e. the main compensation alignment vector D3′) of the firstcompensation alignment vector f1 and the second compensation alignmentvector f2 directs toward the −x direction.

However, the invention is not limited thereto. The third pixel electrode216 can be designed as that shown in FIG. 14B, wherein a fifthcompensation alignment area I5 and a sixth compensation alignment area16 can be further demarked in the third pixel electrode 216 located inthe first region R1 by the third main trunk portions 216 a and 216 b inaddition to the first compensation alignment area I1 and the secondcompensation alignment area 12. Herein, the first compensation alignmentvector f1 of the first compensation alignment area I1, the secondcompensation alignment vector f2 of the second compensation alignmentarea 12, a fifth compensation alignment vector f5 of the fifthcompensation alignment area I5, and a sixth compensation alignmentvector f6 of the sixth compensation alignment area 16 together constructthe main compensation alignment vector D3′.

In addition, the third pixel electrode 216 located in the first regionR1 according to the present embodiment can further include a pluralityof third branch portions 216 e and 216 f connected with the third maintrunk portion 216 a or the third main trunk portion 216 b, wherein thethird branch portions 216 e are located in the fifth compensationalignment area I5 and the third branch portions 216 f are located in thesixth compensation alignment area 16. The direction of the fifthcompensation alignment vector f5 provided by the third branch portions216 e in the fifth compensation alignment area I5 intersects with the xdirection by about 315°. The direction of the sixth compensationalignment vector f6 provided by the third branch portions 216 f in thesixth compensation alignment area 16 intersects with the x direction byabout 45°. The direction of the vector sum (i.e. the main compensationalignment vector D3′) of the first compensation alignment vector f1, thesecond compensation alignment vector f2, the fifth compensationalignment vector f5, and the sixth compensation alignment vector f6directs toward the −x direction.

Referring to FIG. 13 again, the third pixel electrode 216 located in thesecond region R2 has a third compensation alignment area I3 and a fourthcompensation alignment area I4, and a vector sum (i.e. the maincompensation alignment vector D3″) of a third compensation alignmentvector f3 of the third compensation alignment area I3 and a fourthcompensation alignment vector f4 of the fourth compensation alignmentarea I4 is substantially parallel to the first main alignment vector D1.In other words, the vector sum (i.e. the main compensation alignmentvector D3″) formed by the third compensation alignment vector f3 and thefourth compensation alignment vector f4 has the direction opposite tothe direction of the second main alignment vector D2 of the seconddisplay area r2 in the second region R2, such that the main compensationalignment vector D3″ can provide the compensation effect to the seconddisplay area r2 located in the second region R2 when the LCD panel 200Astates in the narrow viewing angle display mode.

The third compensation alignment vector f3 and the fourth compensationalignment vector f4 of the third pixel electrode 216 in the secondregion R2 can be achieved by various ways. For instance, the thirdcompensation alignment vector f3 and the fourth compensation alignmentvector f4 of the third pixel electrode 216 in the second region R2 canbe achieved by the pattern design of the third pixel electrode 216 shownin FIG. 15A. In the present embodiment, the third pixel electrode 216located in the second region R2 can include two third main trunkportions 216 a and 216 b and a plurality of third branch portions 216 cand 216 d connected with the third main trunk portion 216 a or the thirdmain trunk portion 216 b, wherein the extending direction of the thirdmain trunk portion 216 a is parallel to the x direction and theextending direction of the third main trunk portion 216 b is parallel tothe y direction. The third main trunk portion 216 a is substantiallyparallel to the x direction divides the third pixel electrode 216 intothe third compensation alignment area I3 and the fourth compensationalignment area I4. The third branch portions 216 c are disposed in thethird compensation alignment area I3 and intersects with the third maintrunk portion 216 a or the third main trunk portion 216 b by about 45degrees. The third branch portions 216 d are disposed in the fourthcompensation alignment area I4 and intersects with the third main trunkportion 216 a or the third main trunk portion 216 b by about 45 degrees.In addition, the third branch portions 216 c and the third branchportions 216 d are not parallel to each other.

According to the x direction depicted in FIG. 15A, the direction of thethird compensation alignment vector f3 provided by the third branchportions 216 c in the third compensation alignment area I3 intersectswith the x direction by about 315°. The direction of the fourthcompensation alignment vector f4 provided by the third branch portions216 d in the fourth compensation alignment area I4 intersects with the xdirection by about 45°. Accordingly, the direction of the vector sum(i.e. the main compensation alignment vector D3″) of the third alignmentvector f3 and the fourth alignment vector f4 directs toward the +xdirection.

However, the invention is not limited thereto. The third pixel electrode216 located in the second region R2 can be designed as that shown inFIG. 15B, wherein a seventh compensation alignment area 17 and a eighthcompensation alignment area 18 can be further demarked in the thirdpixel electrode 216 located in the second region R2 by the third maintrunk portions 216 a and 216 b in addition to the third compensationalignment area I3 and the fourth compensation alignment area I4. Herein,the third compensation alignment vector f3 of the third compensationalignment area I3, the fourth compensation alignment vector f4 of thefourth compensation alignment area I4, a seventh compensation alignmentvector f7 of the seventh compensation alignment area 17, and a eighthcompensation alignment vector f8 of the eighth compensation alignmentarea 18 together construct the main compensation alignment vector D3″.

In addition, the third pixel electrode 216 located in the second regionR2 according to the present embodiment can further include a pluralityof third branch portions 216 e and 216 f connected with the third maintrunk portion 216 a or the third main trunk portion 216 b, wherein thethird branch portions 216 e are located in the seventh compensationalignment area 17 and the third branch portions 216 f are located in theeighth compensation alignment area 18. The direction of the seventhcompensation alignment vector f7 provided by the third branch portions216 e in the seventh compensation alignment area 17 intersects with thex direction by about 225°. The direction of the eighth compensationalignment vector f8 provided by the third branch portions 216 f in theeighth compensation alignment area 18 intersects with the x direction byabout 135°. The direction of the vector sum (i.e. the main compensationalignment vector D3″) of the third compensation alignment vector f3, thefourth compensation alignment vector f4, the seventh compensationalignment vector f7, and the eighth compensation alignment vector f8directs toward the +x direction, i.e. parallel to the first mainalignment vector D1.

FIG. 16 is a schematic view of an LCD panel under the wide viewing angledisplay mode according to the second embodiment of the invention.Referring to FOG. 16, all the first display areas r1 and all the seconddisplay areas r2 of the sub-pixels 210 in the first region R1 and thesecond region R2 are enabled when the LCD panel 200A states in the wideviewing angle display mode. Furthermore, the compensation display areasr3 in all the sub-pixels 210 located in the first region R1 and thesecond region R2 are disabled. Herein, the first display area r1 and thesecond display area r2 in each sub-pixel 210 provide brightness and thedisplayed brightness presented by each sub-pixel 210 at variant viewingangles complies with the predetermined displayed brightness because thefirst main alignment vector D1 of the first display area r1 differs fromthe second main alignment vector D2 of the second display area r2, suchthat the LCD panel 200A has the wide viewing angle displaycharacteristic.

FIG. 17 is a schematic view of an LCD panel under the narrow viewingangle display mode according to the second embodiment of the invention.Referring to FIG. 17, the first region R1 and the second region R2 areoperated by different methods when the LCD panel 200A states in thenarrow viewing angle display mode. Specifically, driving voltages of thefirst display areas r1 in the first region R1 are substantially greaterthan driving voltages of the second display areas r2 in the first regionR1 and driving voltages of the first display areas r1 in the secondregion R2 are substantially smaller than driving voltages of the seconddisplay areas r2 in the second region R2 when the LCD panel 200A statesin the narrow viewing angle display mode. For instance, in the firstregion R1, the first display area r1 and the compensation display arear3 of each sub-pixel 210 are enabled while the second display area r2 ofeach sub-pixel 210 is disabled. In addition, in the second region R2,the first display area r1 of each sub-pixel 210 is disabled and thesecond display area r2 and the compensation display area r3 of eachsub-pixel 210 are enabled. The first main alignment vector D1 of thefirst display area r1 has the direction opposite to the direction of thesecond main alignment vector D2 of the second display area r2, such thatthe brightness distributions in the first region R1 and the secondregion R2 of the LCD panel 200A are different from each other. Based onsuch circumstance, the user located in the side viewing angle directioncan not see the correct image owing that the brightness distributionpresented at the side viewing angles by the LCD panel 200A do not complywith the predetermined displayed brightness distribution, whichfacilitates the privacy protecting effect.

It is noted that the compensation display areas r3 in all of thesub-pixels 210 are enabled for compensating the brightness presented inthe first region R1 and the second region R2 at the viewing anglesadjacent to the normal viewing angle when the LCD panel 200A of thepresent embodiment states in the narrow viewing angle display mode, suchthat the brightness presented at the viewing angles adjacent to thenormal view angle (i.e. the angles located in the range between about±5° polar viewing angle) can be close to the predetermined displayedbrightness to mitigate the giddy feeling of the user watching thedisplayed image in the normal viewing angle direction.

In other words, the LCD panel 200A under the narrow viewing angledisplay mode can provide desirable display quality to the user in thenormal viewing angle direction by lighting the compensation displayareas r3 and the compensation is further depicted in the following.

FIG. 18A shows the brightness distribution (the relationship between thepolar viewing angle θ and the brightness) presented by the enableddifferent display areas of each sub-pixel in the first region R1 whenthe LCD panel states in the narrow viewing angle display mode accordingto the present embodiment of the invention. FIG. 18B shows thebrightness distribution (the relationship between the polar viewingangle θ and the brightness) presented by the enabled different displayareas of each sub-pixel in the second region R2 when the LCD panelstates in the narrow viewing angle display mode according to the presentembodiment of the invention. Referring to FIG. 18A and FIG. 18B, therelationship between the polar viewing angle θ and the brightnesspresented by the first display area r1 of the sub-pixel 210 is shown inthe drawing (a) of FIG. 18A. The relationship between the polar viewingangle θ and the brightness presented by the second display area r2 ofthe sub-pixel 210 is shown in the drawing (a) of FIG. 18B. Therelationships between the polar viewing angle θ and the brightnesspresented by the compensation display areas r3 in the first region R1and the second region R2 are shown in the drawing (b) of FIG. 18A and inthe drawing (b) of FIG. 18B, respectively.

As shown in the drawing (a) of FIG. 18A and the drawing (a) of FIG. 18B,if the compensation display areas r3 are not disposed in the sub-pixels210 in the first region R1 and the second region R2, the right eye ofthe user (watching the displayed image in the about 5° polar viewingangle) can receive relative weak brightness presented in the firstregion R1 and relative strong brightness presented in the second regionR2 because the brightness in the first region R1 is only provided by thefirst display areas r1 and the brightness in the second region R2 isonly provided by the second display areas r2. At the same time, the lefteye of the user (watching the displayed image in the about −5° polarviewing angle) can receive relative strong brightness presented in thefirst region R1 and relative weak brightness presented in the secondregion R2. As a result, the user may feel giddy owing that the two eyesrespectively receive different brightness presented by the same area.

Nevertheless, the LCD panel 200A of the present embodiment is configuredwith the compensation display areas r3. Under the narrow viewing angledisplay mode, the distribution between the polar viewing angle θ and thebrightness presented in the first region R1 can be the overlap of thedistribution between the polar viewing angle θ and the brightnesspresented by the first display area r1 and the distribution between thepolar viewing angle θ and the brightness presented by the compensationdisplay area r3 as shown in the drawing (c) of FIG. 18A. Similarly, thedistribution between the polar viewing angle θ and the brightnesspresented in the second region R2 can be the overlap of the distributionbetween the polar viewing angle θ and the brightness presented by thesecond display area r2 and the distribution between the polar viewingangle θ and the brightness presented by the compensation display area r3as shown in the drawing (c) of FIG. 18B. It is shown in the drawing (c)of FIG. 18A and the drawing (c) of FIG. 18B that the compensationdisplay areas r3 are enabled in the sub-pixels 210 in the first regionR1 and the second region R2, such that the difference of the brightnessfrom the first region R1 or the second region R2 received by the twoeyes of the users can be reduced under the narrow viewing angle displaymode, which mitigates the problem of giddy feeling of the user watchingthe displayed image in the normal viewing angle direction.

It is noted that the cell gap of the compensation display area r3 can begreater than the cell gaps of the other display areas r1 and r2 so thatthe brightness distribution presented by the compensation display arear3 with respect to variant polar viewing angles θ is relativeconcentrated. Furthermore, the compensation display areas r3 providedifferent main compensation alignment vectors D3′ and D3″ in differentregions R1 and R2. Therefore, the design of the present embodiment isconducive to enhance the display quality of the LCD panel 200A at thenormal viewing angle and the compensation display areas r3 can havesmaller area. As such, the disabled compensation display areas r3 havesmaller area when the LCD panel 200A states in the wide viewing angledisplay mode, which is conducive to achieving higher lighttransmittance. The results listed in table 2 are taken as an example.

TABLE 2 The polar viewing angle 0 (°) along the horizontal axisdirection (0° azimuth viewing The ratio of the brightness in the firstregion angle or 180° azimuth angle) R1 and the brightness in the secondregion R2 5 45 60 No compensation display areas 1.35 47.38 427.14 Thearea ratio of the first display area   8:1 1.21 13.83 113.61 (or thesecond display area) and the   4:1 1.12 8.09 64.98 compensation displayarea 1.75:1 1.01 3.92 31.40

As shown in table 2, the ratio of the brightness in the first region R1and the brightness in the second region R2 at the about 5° polar viewingangle is about 1.12 when the area ratio of the first display area r1 (orthe second display area r2) and the compensation display area r3 in theLCD panel 200A is enhanced to about 4:1, which means the brightness inthe first region R1 is almost identical to the brightness in the secondregion R2 at the about 5° polar viewing angle. As such, the disableddisplay areas occupy smaller area when the LCD panel 200A states in thewide viewing angle display mode, which is conducive to achieving higherlight transmittance of the LCD panel 200A under the wide viewing angledisplay mode.

In addition, the driving method of the LCD panel 200A in the presentembodiment under the narrow viewing angle display mode is similar to thedriving method of the LCD panel 200 in the first embodiment, which isnot iterated here. Nevertheless, the driving method of the LCD panel200A in the present embodiment under the wide viewing angle display modeis different from the driving method of the LCD panel 200 in the firstembodiment. The difference therebetween lies in that the driving voltageof about 0V or a dark voltage is applied to the third pixel electrodes216 when the LCD panel 200A in the present embodiment states in the wideviewing angle display mode such that the compensation display areas r3in the first region R1 and the second region R2 can display a darkimage. Namely, the first display areas r1 and the second display areasr2 located in both the first region R1 and the second region R2 displaythe bright image while the compensation display areas r3 display thedark image. Thereby, the LCD panel 200A can have the wide viewing angledisplay characteristic.

The Third Embodiment

The LCD panel in this embodiment utilizes the compensation designsimilar to the LCD panel described in the second embodiment. However, inthe present embodiment, each of the compensation display areas isdirectly connected with the display areas to accomplish the compensationeffect and further mitigate giddy feeling of the user watching the imagedisplayed by the LCD panel in the normal viewing angle direction.

FIG. 19 is a schematic view of an LCD panel according to a thirdembodiment of the invention. Referring to FIG. 19, an LCD panel 200B inthis embodiment is divided into at least one first region R1 and atleast one second region R2. The first region R1 and the second region R2respectively have a plurality of sub-pixels 210 arranged in an array andeach of the sub-pixels 210 has the first display area r1 providing thefirst main alignment vector D1, the second display area r2 providing thesecond main alignment vector D2, and the compensation display area r3.The directions of the first main alignment vector D1 and the second mainalignment vector D3 are opposite to each other. The cell gap G3 of thecompensation display area r3 is substantially greater than the cell gapG1 of the first display area r1 and also substantially greater than thecell gap G2 of the second display area r2 as shown in FIG. 20.

Furthermore, the compensation display area r3 in each of the sub-pixels210 has a first compensation display area J1 and a second compensationdisplay area J2. The first compensation display area J1 and the firstdisplay area r1 are connected and are driven simultaneously, i.e. thefirst compensation display area J1 and the first display area r1 areenabled simultaneously or disabled simultaneously. The secondcompensation display area J2 and the second display area r2 areconnected and are driven simultaneously, i.e. the second compensationdisplay area J2 and the second display area r2 are enabledsimultaneously or disabled simultaneously. It is noted that the area ofthe first compensation display area J1 is not greater than the area ofthe first display area r1 and the area of the second compensationdisplay area J2 is not greater than the second display area r2.

In the present embodiment, each of the sub-pixels 210 includes the firstpixel electrode 212 and the second pixel electrode 214. The firstdisplay area r1 and the first compensation display area J1 are definedby the first pixel electrode 212 and the second display area r2 and thesecond compensation display area J2 are defined by the second pixelelectrode 214.

The first pixel electrode 212 in the present embodiment can have a firstalignment area K1, a second alignment area K2, a third alignment areaK3, and a fourth alignment area K4, wherein the first alignment area K1and the second alignment area K2 together construct the first displayarea r1 and the third alignment area K3 and the fourth alignment area K4together construct the first compensation display area J1. The firstalignment vector d1 of the first alignment area K1, the second alignmentvector d2 of the second alignment area K2, the third alignment vector d3of the third alignment area K3, and the fourth alignment vector d4 ofthe fourth alignment area K4 together construct the first main alignmentvector D1 and the vector sum of the third alignment vector d3 and thefourth alignment vector d4 is A1 as shown in FIG. 20.

It is noted that the included angle α formed by the third alignmentvector d3 and the x direction and the included angle β formed by thefourth alignment vector d4 and the x direction are preferably greaterthan or equal to about 45 degrees and smaller than about 90 degrees. Assuch, the first compensation display area J1 applied by high drivingvoltage (the voltage applied to the first pixel electrode 212) canprovide the compensation effect to the first display area r1 when theLCD panel 200B in the present embodiment states in the narrow viewingangle display mode.

In the present embodiment, the second pixel electrode 214 has a fifthalignment area K5, a sixth alignment area K6, a seventh alignment areaK7, and an eighth alignment area K8, the fifth alignment area K5 and thesixth alignment area K6 construct the second display area r2, theseventh alignment area K7 and the eighth alignment area K8 construct thesecond compensation display area J2, a vector sum of a fifth alignmentvector d5 of the fifth alignment area K5, a sixth alignment vector d6 ofthe sixth alignment area K6, a seventh alignment vector d7 of theseventh alignment area K7, and an eighth alignment vector d8 of theeighth alignment area K8 construct the second main alignment vector D2,and a vector sum of the seventh alignment vector d7 and the eighthalignment vector d8 is A2 as shown in FIG. 20. In the presentembodiment, the direction of the vector sum A1 can be identical to thesecond main alignment vector D2 and the direction of the vector sum A2can be identical to the first main alignment vector D1.

It is noted that the included angle γ formed by the seventh alignmentvector d7 and the x direction and the included angle δ formed by theeighth alignment vector d8 and the x direction are preferably greaterthan or equal to about 45 degrees and smaller than about 90 degrees. Assuch, the second compensation display area J2 applied by high drivingvoltage (the voltage applied to the second pixel electrode 214) canprovide the compensation effect to the second display area r2 when theLCD panel 200B in the present embodiment states in the narrow viewingangle display mode.

All the first display areas r1 and all the second display areas r2 inthe first region R1 and the second region R2 are enabled when the LCDpanel 200B states in the wide viewing angle display mode. Accordingly,all the first display areas r1, all the second display areas r2, all thefirst compensation display areas J1, and all the second compensationdisplay area J2 in the first region R1 and the second region R2 areenabled when the LCD panel 200B states in the wide viewing angle displaymode. Herein, the displayed brightness of each sub-pixel 210 at variantviewing angles is sufficient because the first main alignment vector D1formed by the first display area r1 and the first compensation displayarea J1 has the direction differs from the direction of the second mainalignment vector D2 formed by the second display area r2 and the secondcompensation display area J2, such that the LCD panel 200B has the wideviewing angle display characteristic.

The first region R1 and the second region R2 are operated by differentmethods when the LCD panel 200B states in the narrow viewing angledisplay mode. Specifically, driving voltages of the first display areasr1 in the first region R1 are substantially greater than drivingvoltages of the second display areas r2 in the first region R1 anddriving voltages of the first display areas r1 in the second region R2are substantially smaller than driving voltages of the second displayareas r2 in the second region R2 when the LCD panel 200B states in thenarrow viewing angle display mode. For instance, in the first region R1,the first display area r1 of each sub-pixel 210 is enabled and thesecond display area r2 of each sub-pixel 210 is disabled. Herein, only aportion of the compensation display areas r3 in the first region R1 areenabled, i.e. only the first compensation display areas J1 among thecompensation display areas r3 in the first region R1 are enabled, whilethe second compensation display areas J2 are disabled. In addition, inthe second region R2, the first display area r1 of each sub-pixel 210 isdisabled and the second display area r2 of each sub-pixel 210 isenabled. Herein, only a portion of the compensation display areas r3 inthe second region R2 are enabled, i.e. only the second compensationdisplay areas J2 among the compensation display areas r3 in the secondregion R2 are enabled, while the first compensation display areas J1 aredisabled.

The first display areas r1 and the first compensation display areas J1in the first region R1 are enabled while the second display areas r2 andthe second compensation display areas J2 in the first region R1 aredisabled, and the second display areas r2 and the second compensationdisplay areas J2 in the second region R2 are enabled while the firstdisplay areas r1 and the first compensation display areas J1 in thesecond region R2 are disabled when the LCD panel 200B states in thenarrow viewing angle display mode. Accordingly, each sub-pixel 210 inthe first region R1 provides displayed brightness by the first displayareas r1 and the first compensation display areas J1 and each sub-pixel210 in the second region R2 provides the displayed brightness by thesecond display areas r2 and the second compensation display areas J2.The first main alignment vector D1 provided by the first display area r1and the first compensation display area J1 has the direction opposite tothe direction the second main alignment vector D2 provided by the seconddisplay area r2 and the second compensation display area J2, such thatthe brightness distributions in the first region R1 and the secondregion R2 of the LCD panel 200B are different from each other. Based onsuch circumstance, the user located in the side viewing angle directioncan not see the correct image owing that the brightness distributionpresented by the LCD panel 200B at the side viewing angles do not complywith the predetermined displayed brightness distribution, whichfacilitates the privacy protecting effect.

In addition, as shown in FIG. 20 which is the cross-sectional view ofthe sub-pixel 210 taken along the sectioning line A-A′ and sectioningline B-B′ of FIG. 19, the cell gap G3 of the compensation display arear3 in the LCD panel 200B according to the present embodiment issubstantially greater than the cell gap G1 of the first display area r1and the cell gap G2 of the second display area r2. Accordingly, thebrightness distribution provided by the compensation display area r3 ismore concentrated around the normal viewing angle and the small polarviewing angle than that provided by the first display area r1 and thesecond display area r2. The compensation display areas r3 can providethe compensation function for compensating the brightness presented inthe first region R1 and the second region R2 at the viewing anglesadjacent to the normal viewing angle, such that the brightness presentedby the first region R1 and the second region R2 of the LCD panel 200 atthe small side viewing angles can be close to the predetermineddisplayed brightness to mitigate the giddy feeling of the user watchingthe displayed image in the normal viewing angle direction. The resultslisted in tables 3 and 4 are taken as an example.

G1=G2=3.5 μm; G3=7 μm

TABLE 3 The ratio of the brightness in the first region R1 and thebright- ness in the Driving voltage (V) second region R2 2.3 2.6 2.9 3.23.5 4 5 Polar θ = 5° 1.33 1.12 1.00 1.07 1.11 1.12 1.08 viewing θ = 45°1.08 1.64 3.36 6.60 5.98 3.03 1.54 angle θ = 60° 1.58 3.21 13.74 136.0110.43 3.01 1.46 (θ)

G1=G2=G3=3.5 μm

TABLE 4 The ratio of the brightness in the first region R1 and thebright- ness in the Driving voltage (V) second region R2 2.3 2.6 2.9 3.23.5 4 5 Polar θ = 5° 2.27 1.63 1.39 1.26 1.18 1.11 1.04 viewing θ = 45°8.73 99.23 108.54 14.63 6.11 2.87 1.55 angle θ = 60° 3.92 11.82 94.16139.87 16.34 4.60 1.85 (θ)

The table 3 shows the ratio of the brightness in the first region R1 andthe brightness in the second region R2 at variant polar viewing angles θwith respect to different driving voltages applied to the first pixelelectrodes 212 in the first region R1 and the second pixel electrodes214 in the second region R2 when the LCD panel 200B of the presentembodiment states in the narrow viewing angle display mode. The table 4shows the ratio of the brightness in the first region R1 and thebrightness in the second region R2 at variant polar viewing angles θwith respect to different driving voltages according to a comparedexample when the LCD panel of the compared example states in the narrowviewing angle display mode. The difference between the LCD panel of thepresent embodiment and the LCD panel of the compared example lies inthat in the LCD panel of the present embodiment, the cell gap G1 of thefirst display areas r1 and the cell gap G2 of the second display areasr2 are about 3.5 μm while the cell gap G3 of the compensation displayareas r3 is about 7 μm and in the LCD panel of the compared example, thecell gap G1 of the first display areas r1, the cell gap G2 of the seconddisplay areas r2, and the cell gap G3 of the compensation display areasr3 are about 3.5 μm.

Comparing the tables 3 and 4, the ratio of the brightness in the firstregion R1 and the brightness in the second region R2 is close to 1.1under variant driving voltages and at the about 5° polar viewing anglewhen the cell gap G3 of the compensation display areas 3 r is increasedto about 7 μm. That is to say, the brightness in the first region R1 andthe brightness in the second region R2 are quite close under variantdriving voltages and at the about 5° polar viewing angle when the cellgap G3 of the compensation display areas 3 r is increased to about 7 μm,which is conducive to mitigate the giddy feeling of the user watchingthe display image under the narrow viewing angle display mode in thenormal viewing angle direction.

The Fourth Embodiment

FIG. 21 is a schematic diagram of a pixel structure according to asub-pixel in one LCD panel of one embodiment of the invention. FIG. 22Aand FIG. 22B illustrate the display status of the LCD panel using thesub-pixel depicted in FIG. 21 under the wide viewing angle display modeand the narrow viewing angle display mode, respectively.

As shown in FIG. 21, FIG. 22A, and FIG. 22B, an LCD panel 200C isdivided into at least one first region R1 and at least one second regionR2. Two first regions R1 and two second regions R2 illustrated in FIG.21 are taken as an example. The first regions R1 and the second regionsR2 respectively are formed with a plurality of sub-pixels 210, whereinthe color displayed by the sub-pixels 210 can include red, green, blue,yellow, and the like, but the invention is not limited thereto. Each ofthe sub-pixels 210 includes a first display area r1 and a second displayarea r2. The first display area r1 is divided into a plurality of firstalignment areas K1 by a first horizontal baseline H1 and a firstvertical baseline V1, and the first alignment areas K1 respectively havea liquid crystal alignment.

Specifically, the first horizontal baseline H1 divides the first displayarea r1 evenly such that the liquid crystal alignment in the firstdisplay area r1 is symmetrically distributed along the first horizontalbaseline H1. The first vertical baseline V1 divides the first displayarea r1 into the first sub-display area r1-a and the second sub-displayarea r2-a, wherein the area of the first sub-display area r1-a differsfrom the area of the second sub-display area r1-b. In the presentembodiment, the area of the first sub-display area r1-a is substantiallygreater than the area of the second display area r1-b and the cell gapof the first sub-display area r1-a can be identical to or different fromthe cell gap of the second sub-display area r1-b. For example, the cellgap of the first sub-display area r1-a can be substantially smaller thanthe cell gap of the second sub-display area r1-b.

The second display area r2 is divided into a plurality of secondalignment areas K2 by the second horizontal baseline H2 and the secondvertical baseline V2. Each of the second alignment areas K2 has a liquidcrystal alignment and the liquid crystal alignments of the secondalignment areas K2 are different from each other. The second horizontalbaseline H2 divides the second display area r2 evenly such that theliquid crystal alignments of the second display area r2 aresymmetrically distributed with respect to the second horizontal baselineH2 while the second vertical baseline V2 divides the second display arear2 unevenly into a third sub-display area r2-a and a fourth sub-displayarea r2-b having an area different from an area of the third sub-displayarea r2-a. In the present embodiment, the area of the third sub-displayarea r2-a is substantially greater than the area of the fourth displayarea r2-b and the cell gap of the third sub-display area r2-a can besubstantially identical to or different from the cell gap of the fourthsub-display area r2-b. For example, the cell gap of the thirdsub-display area r2-a can be substantially smaller than the cell gap ofthe fourth sub-display area r2-b.

Based on the aforesaid description, the pixel structure havingasymmetric structure with respect to the horizontal direction isprovided as shown in FIG. 21, FIG. 22A, and FIG. 22B.

The currently provided pixel structure which has the liquid crystalalignment asymmetrically distributed with respect to the horizontaldirection is achieved by dividing the LCD panel into a plurality ofdisplay blocks (such as the first regions R1 and the second regions R2)respectively having the alignment different from one another, whereinthe display blocks are alternatively arranged in the line direction andthe row direction. Moreover, the display blocks are, for example,arranged in the checkerboard arrangement when being switched to thenarrow viewing angle display mode. During displaying the image, thesub-pixels in one display block turn on one of the display areas thereinand thus the user located in the side viewing angle direction seesvarious brightness distribution, which causes the image interference.

However, owing that the left eye and the right eye of the user areseparated by a distance, the left eye and the right eye of the user seethe image displayed by the LCD panel at the angle ranging about theabout ±5° polar viewing angle rather than at about 0° polar angle whenthe user is located in the normal viewing angle direction. The varianceof the viewing angles can cause the left eye and the right eye of theuser to see different displayed brightness, which makes the parallaxwhen the user watches the displayed image in the normal viewing angledirection. The phenomenon is further worse in the pixel structure havingthe liquid crystal alignment asymmetrically distributed with respect tothe horizontal direction.

To mitigate the parallax in the present embodiment, the display areaspredetermined to be turned off are not completely turned off duringdisplaying the image. That is, a lower gray voltage rather than about 0Vcan be applied to the display areas predetermined to be turned off, suchthat the difference between the brightness received by the left eye andthe right eye of the user at the viewing angles between about +5° polarviewing angle and about −5° polar viewing angle can be reduced.Simultaneously, with respect to the compensation voltage applied to thedisplay areas predetermined to be turned off, a fixed voltage can beserved as the compensation voltage no matter the value of the gray levelthe image is predetermined to display, or variant voltages can be servedas the compensation voltages corresponding to the value of the graylevel the image is predetermined to display for compensating theparallax caused in different displayed gray levels to a certain extent.The lower the compensation voltage the better the privacy protectingeffect and the higher the compensation voltage the smaller the parallaxextent in the normal viewing angle.

More specifically, in the LCD panel shown in FIG. 21, FIG. 22A, and FIG.22B, a first driving voltage V1 of the first display areas r1 displayinga first normal viewing brightness in the first region R1 issubstantially greater than a second driving voltage V2 of the firstdisplay areas r1 displaying the first normal viewing brightness in thesecond region R2, and the second driving voltage V2 is substantiallygreater than 0 when the LCD panel 200C states in the narrow viewingangle mode.

In addition, the first driving voltage V1 of the first display areas r1displaying the first normal viewing brightness in the first region R1 issubstantially greater than a third driving voltage V3 of the seconddisplay areas r2 displaying the first normal viewing brightness in thefirst region R1, and the first driving voltage V1 of the first displayareas r1 displaying the first normal viewing brightness in the firstregion R1 is substantially equal to a fourth driving voltage V4 of thesecond display areas r2 displaying the first normal viewing brightnessin the second region R2 when the LCD panel 200C states in the narrowviewing angle mode. The third driving voltage V3 of the second displayareas r2 displaying the first normal viewing brightness in the firstregion R1 is substantially equal to the second driving voltage V2 of thefirst display areas r1 displaying the first normal viewing brightness inthe second region R2. It is noted that the driving method of the LCDpanel 200C mentioned above can be apply in the LCD panel 200B of thethird embodiment to facilitate the LCD panel 200B of the thirdembodiment having better display effect.

According to the following table 5, under the condition that the cellgaps of the first and the second display areas r1 and r2 in the firstregion R1 and the second region R2 are the same, the ratio of thebrightness in the first and the second regions R1 and R2 seen by theleft eye and the right eye of the user at the about 5° polar viewingangle is changed from about 1.377 to about 1.306 when the drivingvoltage (i.e. the second or the third voltage mentioned above) of thesecond display area r2 displaying the first normal viewing brightness inthe first region R1 for compensating the parallax is about 2.175V, whichmitigates the parallax effect and the privacy protecting effect may begetting worse due to the compensation of the voltage while the ratio ofthe brightness in the first and the second regions R1 and R2 can bemaintained in around 5.

TABLE 5 The ratio of the brightness in the first region R1 and thebright- The second driving voltage ness in the (or the third drivingvoltage) second region R2 0 V 2.1 V 2.175 V 2.2 V 2.3 V The side  5°1.377 1.343 1.306 1.290 1.222 viewing angle 45° 87.346 8.392 4.974 4.3062.719

In light of the foregoing, the LCD panel according to the inventionimproves the problem of giddy feeling of the user when the user watchesthe image displayed by the LCD panel under the narrow viewing angledisplay mode in the normal viewing angle direction by configuring thecompensation display area or modulating the brightness of the displayareas and the LCD panel according to the invention also providesdesirable privacy protecting effect.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of theinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the invention covermodifications and variations of this invention provided they fall withinthe scope of the following claims and their equivalents.

What is claimed is:
 1. An LCD panel divided into at least one firstregion and at least one second region, the first region and the secondregion respectively having a plurality of sub-pixels arranged in anarray, and each of the sub-pixels having: a first display area providinga first main alignment vector; a second display area providing a secondmain alignment vector, and a direction of the first main alignmentvector being opposite to a direction of the second main alignmentvector; a first compensation display area, a cell gap of the firstcompensation display area being substantially greater than a cell gap ofthe first display area, the first compensation display being connectedwith the first display area, and the first compensation display area andthe first display area being simultaneously enabled or disabled; and asecond compensation display area, a cell gap of the second compensationdisplay area being substantially greater than a cell gap of the seconddisplay area, the second compensation display being connected with thesecond display area, and the second compensation display area and thesecond display area being simultaneously enabled or disabled, whereindriving voltages of the first display areas and the first compensationdisplay areas in the first region are substantially greater than drivingvoltages of the second display areas and the second compensation displayareas in the first region, and driving voltages of the first displayareas and the first compensation display areas in the second region aresubstantially smaller than driving voltages of the second display areasand the second compensation display areas in the second region.
 2. TheLCD panel of claim 1, wherein an area of the first compensation displayarea is not greater than an area of the first display area and an areaof the second compensation display area is not greater than an area ofthe second display area.
 3. The LCD panel of claim 1, wherein each ofthe sub-pixel comprises a first pixel electrode and a second pixelelectrode, the first pixel electrode defines the first display area andthe first compensation display area, and the second pixel electrodedefines the second display area and the second compensation displayarea.
 4. The LCD panel of claim 3, wherein the first pixel electrode hasa first alignment area, a second alignment area, a third alignment area,and a fourth alignment area, the first alignment area and the secondalignment area construct the first display area, the third alignmentarea and the fourth alignment area construct the first compensationdisplay area, a vector sum of a first alignment vector of the firstalignment area, a second alignment vector of the second alignment area,a third alignment vector of the third alignment area, and a fourthalignment vector of the fourth alignment area constructs the first mainalignment vector, and a vector sum of the third alignment vector and thefourth alignment vector is substantially parallel to the second mainalignment vector.
 5. The LCD panel of claim 4, wherein an included anglebetween the third alignment vector and the second main alignment vectorand an included angle between the fourth alignment vector and the secondmain alignment vector are greater than or equal to 45 about degrees andsmaller than about 90 degrees.
 6. The LCD panel of claim 3, wherein thesecond pixel electrode has a fifth alignment area, a sixth alignmentarea, a seventh alignment area, and an eighth alignment area, the fifthalignment area and the sixth alignment area construct the second displayarea, the seventh alignment area and the eighth alignment area constructthe second compensation display area, a vector sum of a fifth alignmentvector of the fifth alignment area, a sixth alignment vector of thesixth alignment area, a seventh alignment vector of the seventhalignment area, and an eighth alignment vector of the eighth alignmentarea constructs the second main alignment vector, and a vector sum ofthe seventh alignment vector and the eighth alignment vector issubstantially parallel to the first main alignment vector.
 7. The LCDpanel of claim 6, wherein an included angle between the seventhalignment vector and the first main alignment vector and an includedangle between the eighth alignment vector and the first main alignmentvector are greater than or equal to about 45 degrees and smaller thanabout 90 degrees.
 8. The LCD panel of claim 1, wherein cell gaps of thefirst compensation display area and the second compensation display areaare substantially 7 μm and cell gaps of the first display area and thesecond display area are substantially 3.5 μm.
 9. An LCD panel comprisingat least one first region and at least one second region, wherein thefirst region and the second region respectively have a plurality ofsub-pixels arranged in an array, and each of the sub-pixels comprising:a first display area divided into a plurality of first alignment areasby a first horizontal baseline and a first vertical baseline, the firstalignment areas respectively having a liquid crystal alignment, and theliquid crystal alignments of the first alignment areas are differentfrom one another; and a second display area divided into a plurality ofsecond alignment areas by a second horizontal baseline and a secondvertical baseline, the second alignment areas respectively having aliquid crystal alignment, and the liquid crystal alignments of thesecond alignment areas are variant, wherein a first driving voltage ofthe first display areas in the first region is substantially greaterthan a second driving voltage of the first display areas in the secondregion, and the second driving voltage is substantially greater than 0when the LCD panel displays a first normal viewing brightness under anarrow viewing angle display mode.
 10. The LCD panel of claim 9, whereinthe first driving voltage of the first display areas in the first regionis substantially greater that a third driving voltage of the seconddisplay areas in the first region, and the first driving voltage of thefirst display areas in the first region is substantially equal to afourth driving voltage of the second display areas in the second regionwhen the LCD panel displays the first normal viewing brightness underthe narrow viewing angle display mode.
 11. The LCD panel of claim 9,wherein the second driving voltage of the second display areas locatedin the first region is about 2.175V when displaying the first normalviewing brightness.
 12. The LCD panel of claim 9, wherein the firsthorizontal baseline divides the first display area evenly such that theliquid crystal alignments of the first display area are symmetricallydistributed with respect to the first horizontal baseline while thefirst vertical baseline divides the first display area unevenly into afirst sub-display area and a second sub-display area having an areadifferent from an area of the first sub-display area; and the secondhorizontal baseline divides the second display area evenly such that theliquid crystal alignments of the second display area are symmetricallydistributed with respect to the second horizontal baseline while thesecond vertical baseline divides the second display area unevenly into athird sub-display area and a fourth sub-display area having an areadifferent from an area of the third sub-display area.
 13. The LCD panelof claim 12, wherein an area of the first sub-display area issubstantially greater than an area of the second sub-display area and anarea of the third sub-display area is substantially greater than an areaof the fourth sub-display area.
 14. The LCD panel of claim 13, wherein acell gap of the first sub-display area is substantially smaller than acell gap of the second sub-display area and a cell gap of the thirdsub-display area is substantially smaller than a cell gap of the fourthsub-display area.